Debugger: Compile with QT_NO_CAST_FROM_ASCII.

(except gdbmi.cpp, name_demangler.cpp). Remove some unneeded
conversions, change some maps to take QByteArray keys.

Change-Id: I010f1251998a441fe5c8c87901b1e0c277c0391c
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/watchdelegatewidgets.cpp

@@ -116,7 +116,7 @@ QValidator::State IntegerValidator::validateEntry(const QString &s, int base, bo
         return QValidator::Intermediate;
     int pos = 0;
     // Skip sign.
-    if (signedV && s.at(pos) == '-') {
+    if (signedV && s.at(pos) == QLatin1Char('-')) {
         pos++;
         if (pos == size)
             return QValidator::Intermediate;